Today, in widely used server systems, virtualization is widely performed. In other words, so-called virtualization of the server is performed. By virtualizing the server, it is possible to enhance the efficiency of utilization of physical resources on the server side.
However, enhancing the efficiency of utilization on the server side (CPU side) results in burden on an I/O (input/output device) side being disadvantageously increased to cause further complication.
For example, due to a request from a user, it may be necessary to connect an arbitrary virtual server to an arbitrary network. In this case, in tell is of security, an individual physical I/O is often provided, and this causes an increase in the number of I/Os.
For example, it is necessary to perform the sharing of storage in order to store a virtual server. Consequently, however, it is also necessary to provide an EtherNet (registered trademark) and a fiber channel and the like according to the request of the user, and further necessary to increase the number of various physical I/Os, with the result that the system is likely to be complicated.
For example, in order to manage a virtual environment, it may be necessary to provide a dedicated I/O.
For example, the efficiency of utilization of the server is enhanced by the virtualization of the server, and thus a band consumed by the I/O is increased, with the result that the bandwidth of an I/O bus may be a bottleneck in today's computer systems.
Improved Conventional Technologies
In order to solve the problems of the I/O described above, various technologies have been developed.
As a first improved conventional technology, there is a technology relating to the sharing/virtualization of storage. This technology is intended to enhance the operating rate of storage by the sharing/virtualization of storage.
Examples of such technology include patent literature 1, which will be described later, and the like.
A second improved conventional technology is a method (such as patent literatures 2 and 3) of sharing an I/O adapter from a plurality of computers and a method (patent literature 4) of performing DMA using a virtual address.
As a third improved conventional technology, virtualization and the like of a network are known.
However, the efficiency of storage and USBs and the like are only partially enhanced with these methods, with the result that it may be difficult to solve the problem of the entire I/O.